A Lithium-ion battery SOC estimation method considering mechanical strain

Abstract

The invention discloses a lithium ion battery SOC estimation method considering mechanical strain. The method comprises the following steps: performing a charging and discharging experiment on the lithium-ion battery to obtain experimental data; establishing a basic strain model of the lithium-ion battery and a battery strain temperature compensation model; selecting an equivalent circuit model of the lithium-ion battery and identifying model parameters; determining the system State equation and measurement equation, introduce the battery basic strain model into the measurement equation; input the real-time measured data into the temperature compensation model to obtain the temperature compensation value of the battery strain, subtract the temperature compensation value from the real-time measured battery strain value, Obtain the basic strain value of the battery; establish an extended Kalman filter SOC estimator to estimate the battery SOC online. The present invention can provide more effective information for the battery management system, thereby improving the accuracy and reliability of lithium-ion battery SOC estimation, enhancing the robustness of the battery management system, thereby improving the use and maintenance efficiency of the battery, and prolonging the battery life. usage time.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a method for estimating the SOC of lithium ion batteries considering mechanical strain. Background technique [0002] Since the beginning of the new century, factors such as energy crisis, environmental pollution and energy security have pushed lithium-ion batteries to the stage of history, and become one of the focuses in the field of new energy. Compared with traditional nickel-cadmium batteries and lead-acid batteries, lithium-ion batteries are gradually favored by manufacturers and consumers due to their many outstanding advantages. The advantages include: long cycle life, good environmental protection (lead and cadmium enter the environment It is very harmful to the human body), fast charging speed, high monomer voltage, weight specific energy, no memory effect, etc. [0003] During the operation of lithium-ion batteries, the battery management system (Battery...

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Problems solved by technology

[0007] In order to overcome the technical problem that the battery SOC estimation accuracy of the existing lithium-ion battery management system cannot be further improved, the present invention provides a lithium-ion battery SOC estimation method considering mechanical strain

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